This invention relates to drill steel stabilizers useful in the rotary method of boring earth formations.
It is known to provide a rotary drill string with one or more replaceable sleeve, fixed blade type stabilizers. See for example U.S. Pat. No. 3,754,609 to Garrett, whose disclosure is incorporated herein by reference, wherein the replaceable sleeve is threaded to a special mandrel and captured between a mandrel shoulder and the shoulder formed by the mouth of a threaded box screwed onto the mandrel. Some of the relevant prior art is discussed in detail in the Garrett patent. See Also U.S. Pat. No. 2,589,534 to Buttolph wherein (FIG. 5) a replaceable sleeve 12 is screwed onto a mandrel, the lower end of the sleeve being provided with an inturned flange which engages a shoulder on a mandrel, the upper end of the sleeve being connected to the mandrel by companion grooves and locking balls. U.S. Pat. No. 2,307,688 to Larson shows a combination sucker rod guide and paraffin scraper in which a sleeve around a double pin connector is captured between shoulders on the sucker rod boxes screwed to the connector and an inturned flanges on the upper end of the sleeve engages a shoulder on the connector. U.S. Pat. No. 2,440,441-Hanes shows a replaceable wear sleeve for a tool joint wherein there are cooperating tapers on the sleeve and tool joint. U.S. Pat. No. 2,620,164 to Burris shows a key seat wiper including a sleeve mounted for axial travel on a mandrel between an upper disengaged position and a lower engaged position in which an internal spline on the sleeve engages an external spline on the mandrel. Yancey's U.S. Pat. No. 2,794,617 shows a "conventional reamer" connected just above a drill bit and just below a circulation booster. U.S. Pat. No. 2,869,827 to Cook shows a stabilizer sleeve having a retaining ring screwed into its upper end. The use of tungsten carbide inserts for wear protection of a drill pipe coupling is shown in U.S. Pat. No. 3,054,647 to Von Rosenburg. Sintered tungsten carbide hard facing for the outer periphery and leading edge of stabilizer blades is shown in the aforementioned Garrett patent. A stabilizer connected just above a tricone rock bit is shown in U.S. Pat. No. 3,370,657 to Antle. Screwed on stabilizer sleeves are shown in U.S. Pat. Nos. 1,607,941 (Bowser), 1,770,207 (Helmling), 1,803,267 (McCloskey). A rubber buffer at the lower end of a drill steel guide is shown in U.S. Pat. No. 2,177,300 to Kellegrew, the guide being just above the bit. A directive shell is shown mounted just above the drill bit in U.S. Pat. No. 2,323,027 to Gerstenkorn. Rotary shouldered connections with multiple engaged surfaces are shown in Griffin Pat. No. 2,636,753 and the references cited therein.